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GHSA-gmg5-r3c4-3fm9 CVE-2019-10226

Withdrawn Advisory: Fat Free CRM Cross-site Scripting vulnerability

Medium Withdrawn Feb 23, 2024 RubyGems
Severity
5.4 / 10
Medium · CVSS 3.0
Exploit chance (EPSS)
4.70%
Chance of exploitation in the next 30 days. Higher than 91.81% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Fix
None yet
No fixed version published

Description

Withdrawn

This advisory has been withdrawn because the CVE has been disputed and the underlying vulnerability is likely invalid. This link is maintained to preserve external references.

According to maintainers of Fat Free CRM, the CRM comment feature allows certain HTML markup, but santizes the output when rendered to page. This allows safe tags (such as <h1> which the author tested and reported as a vulnerability) but correctly disallows <script> tags and other dangerous entities.

Original Description

HTML Injection has been discovered in the v0.19.0 version of the Fat Free CRM product via an authenticated request to the /comments URI.

Affected versions

RubyGems

PackageVulnerableFixed in
fat_free_crm
<= 0.19.0
No fix yet

How to fix

No fixed version has been published yet. Until one is, remove or replace the package, or turn off or isolate the affected feature. This page updates when a fix ships.

Severity breakdown

CVSS 3.0 5.4

CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

Weakness

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

How to prevent it
  • Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482]. Examples of libraries and frameworks that make it easier to generate properly encoded output include Microsoft's Anti-XSS library, the OWASP ESAPI Encoding module, and Apache Wicket.
  • Implementation, Architecture and Design: Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages. Study all expected communication protocols and data representations to determine the required encoding strategies. For any data that will be output to another web page, especially any data that was received from external inputs, use the appropriate encoding on all non-alphanumeric characters. Parts of the same output document may require different encodings, which will vary depending on whether the output is in the: HTML body Element attributes (such as src="XYZ") URIs JavaScript sections Cascading Style Sheets and style property etc. Note that HTML Entity Encoding is only appropriate for the HTML body. Consult the XSS Prevention Cheat Sheet [REF-724] for more details on the types of encoding and escaping that are needed.
  • Architecture and Design, Implementation: Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
  • Architecture and Design: For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
  • Architecture and Design: If available, use structured mechanisms that automatically enforce the separation between data and code. These mechanisms may be able to provide the relevant quoting, encoding, and validation automatically, instead of relying on the developer to provide this capability at every point where output is generated.
  • Implementation: Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8. When an encoding is not specified, a downstream component may choose a different encoding, either by assuming a default encoding or automatically inferring which encoding is being used, which can be erroneous. When the encodings are inconsistent, the downstream component might treat some character or byte sequences as special, even if they are not special in the original encoding. Attackers might then be able to exploit this discrepancy and conduct injection attacks; they even might be able to bypass protection mechanisms that assume the original encoding is also being used by the downstream component. The problem of inconsistent output encodings often arises in web pages. If an encoding is not specified in an HTTP header, web browsers often guess about which encoding is being used. This can open up the browser to subtle XSS attacks.
  • Implementation: With Struts, write all data from form beans with the bean's filter attribute set to true.
  • Implementation: To help mitigate XSS attacks against the user's session cookie, set the session cookie to be HttpOnly. In browsers that support the HttpOnly feature (such as more recent versions of Internet Explorer and Firefox), this attribute can prevent the user's session cookie from being accessible to malicious client-side scripts that use document.cookie. This is not a complete solution, since HttpOnly is not supported by all browsers. More importantly, XmlHttpRequest and other powerful browser technologies provide read access to HTTP headers, including the Set-Cookie header in which the HttpOnly flag is set.
  • Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright. When dynamically constructing web pages, use stringent allowlists that limit the character set based on the expected value of the parameter in the request. All input should be validated and cleansed, not just parameters that the user is supposed to specify, but all data in the request, including hidden fields, cookies, headers, the URL itself, and so forth. A common mistake that leads to continuing XSS vulnerabilities is to validate only fields that are expected to be redisplayed by the site. It is common to see data from the request that is reflected by the application server or the application that the development team did not anticipate. Also, a field that is not currently reflected may be used by a future developer. Therefore, validating ALL parts of the HTTP request is recommended. Note that proper output encoding, escaping, and quoting is the most ef
  • Architecture and Design: When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.
  • Operation: Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].
  • Operation, Implementation: When using PHP, configure the application so that it does not use register_globals. During implementation, develop the application so that it does not rely on this feature, but be wary of implementing a register_globals emulation that is subject to weaknesses such as CWE-95, CWE-621, and similar issues.

References

Timeline

  1. Published
  2. Withdrawn
  3. Last updated by the source
  4. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-9pm8-vwc5-w2hm
Fat Free CRM has BOLA in DELETE /emails/:id - Any authenticated user can hit this endpoint and delete emails by ID
Low Also affects fat_free_crm
GHSA-p75c-5x3h-cxcg
Fat Free CRM vulnerable to Remote Denial of Service via Tasks endpoint
Medium Also affects fat_free_crm
GHSA-mcvq-7xjq-46x6
Fat Free CRM contains Cross-site Request Forgery vulnerablilities
Medium Also affects fat_free_crm
GHSA-f25h-3mj6-4jpg
Fat Free CRM vulnerable to Exposure of Sensitive Information
Medium Also affects fat_free_crm
GHSA-g897-cgfc-7q8v
Fat Free CRM has fixed token value
Medium Also affects fat_free_crm
GHSA-9ggp-5rf4-x7q9
Fat Free CRM vulnerable to SQL Injection
Medium Also affects fat_free_crm
GHSA-4xq9-vw89-p5cx
Fat Free CRM allows remote attackers to obtain sensitive information via a direct request
Medium Also affects fat_free_crm
GHSA-wcfx-3m6v-4frg
Fat Free CRM subject to Cross-site Scripting
Medium Also affects fat_free_crm
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